The Great Great Lakes

Superlatives are in order when talking about the Great Lakes of North America! As a body of water half the size of the Mediterranean Sea and stretching more than a third across North America, the Great Lakes are the largest freshwater chain in the world and contain about one-fifth of the world's fresh water. Forty million people live and work in the basin and many more visit each year. The Great Lakes, their connecting channels and the St. Lawrence River have been the key to the development of the industrial heartland of North America providing economic and efficient transportation; low-cost hydroelectric power; abundant water supplies fbr domestic, agricultural and industrial needs; extensive recreational opportunities and for depositing municipal and industrial discharges. Despite their tremendous areas and depth, the Great Lakes do not have an unlimited assimilative capacity and do in fact suffer from widespread diverse sources of pollution. In addition, water levels and flows in the basin are important because they affect so many sectors.